Stabilized aqueous suspension of calcium (-) (cis-1,2-epoxypropyl)-phosphonate

ABSTRACT

Stabilized aqueous suspensions of calcium (-) (cis-1,2epoxypropyl)-phosphonate.

United States Patent Allen et al.

[151 3,678,163 [4 1 July 18,1972

[54] STABILIZED AQUEOUS SUSPENSION OF CALCIUM(-) (CIS-l,2- EPOXYPROPYL)-PHOSPHONATE [72] Inventors: Donald J. Allen, Gwynedd; Joseph L. O-

Nelll, Lafayette Hill, both of Pa. [73] Assignee: Merck & Co., Inc., Rahway, NJ. [22] Filed: June 2, 1969 21 Appl. No.: 829,785

[5 2] US. Cl ..424/203 [51] Int. Cl. ...A6lu 27/00 58] Field of Search ..424/203 Derwent Farmdoc No. 35,893, BE 718,507, pages 105- 107 and 117-127 Primary Examiner-Stanley J. Friedman Attorney-John Frederick Gerkens, J. Jerome Behan and 1. Louis Wolk [57] ABSTRACT Stabilized aqueous suspensions of calcium (cis-1,2-epoxypropyl)-phosphonate.

1 Claim, No Drawings This invention relates to stabilized aqueous suspensions in Aqueous suspensions of the calcium salt containing the particular combination of surface active agents can be heated to 121C. and cooled to 20C. with no measurable change in particle size when observed microscopically.

an antibacterial agent. More particularly, it relates to aqueous The pharmaceutical Suspensions f h present invention suspensions of the potent antibiotic calcium (-)(cis-l,2-epoxntai f om 0,5 to 50 ercent of al ium (-)(cis-l,2-e ox- XP PYU'P P Stabilized g l Particle Size altefaypropyl)-phosphonate, 0.05 to 1.0 percent sodium carboxy the use of Pfmlcular Surface actlveagemsymethyl-cellulose, 0.1 to 1.0 percent lecithin, and 0.05 to 5 of Y t e sta i ize sus ensions o is invention is to 35.2 erwhich are active in inhibiting the growth of both gram-positive cent calcium -5 3- 1 2 epOxyp1-opy1)-phosphonate, 0 4 to and gram'negative Pathogenic bacteria Salts of ('X 'L 0.7 percent sodium carboxymethylcellulose, 0.5 to 0.6 per- P yp 1 y )-p p acid are useful in the treatment of cent lecithin, and 0.4 to 1.25 percent Polysorbate 80. diseases caused by bacterial infection in man and animals, and 1 The calcium )(Cis 12 epoxypropy|) phosphonme Salt arePmiclflarly valuflble in this respect, Since y are active may be administered alone or in combination with other agamst resls mm Straws ofpau'fogensbiologically active ingredients and especially with other anacgl l lag gz ez foii lti :2 Se 5121;322:3251;P33233323: tibacten'al agents such as erythromycin, benzathine penicillin, chloram henicol, and calcium tetrac cline. In addition, nontoxic when employed for combatting bacterial infections suspensigns of the calcium salt may also :omain other salts of in man and lower animals. The salt may be administered orally )(cis 12 epxypropy]) phosphonic acid, such as mono and in a dosage form such as capsules or tablets, or in a liquid soludi sdium salts monosodium monopotassium magnesium, tion or suspension. Alternatively, the calcium salt may be adaluminum and amine salts thereof ministered par enterally in solution or suspension by injection w aqueous Suspensions of calcium 1n anstirltlsnfgeclll t-ical Suspensions the drug particles are ypropyh-phosphgnlate are used afor tipmbatting) bacerial infect;

t1ons 1n man an ower amm s, t e ma e a ministere suspended in a saturated solution of the drug in the suspending orally or parenterally These formulgtionsy can be prepared 3.2??32223 32f 5123;" 32$??? iifiiZiLflllifiiiiiFlZZ 5 113 1353;3 ;;;jgg1 ';;g; suspension Since a pharmaceutical suspension can be Good results are obtained in the treatment and control of pected to be subjected to variations in temperature from the bacterial infections in animals and adult humans by adminis time it is manufactured until used, the drug will be subject to nation of from about one fourth to 4 gm/day of dissolution before ultimate use. One result of this crystallizaepoxypropyl) phosphomc acid equivalerm It will of course tion process is that the suspended drug particles are subject to be understood that the optimum dose in any given instance Substantial increase in their size and change n f .Such will depend upon the type and severity of infection to be and p y Stability and aesthetic a1 pp use, oiksutt h lajd ustments be1ng within the sk1ll of the pract1 In general, the solubility of most substances increases with .11;; g f y the applicants for y g to decrease. This decrease in the fraction in suspension is giz f i i gg gj fif gl 232 33 'mphed or manifested by enlargement of the suspended drug particles n p app and frequently by a change in their shape. Calcium (-)(cisl ,2- EXAMPLE 1 epoxypropyl)-phosphonate is an atypical compound in that its 4 v I equilibrium solubility decreases with an increase in tempera- Sterile, lsotomc, aqueous suspeflslons 0f calclum tul-e asis Shownin Table 1 I 1,2-epoxypropyl)-phosphonate suitable for parenteral ad- TABLE 1 ministration are prepared in the following manner: Solubility of Calcium (Cis-l ,2-Epoxypropyl)-Phosphonate Temperature no s l Ingredients Concentration mg./ml.

25 Calcium (-)(cis-l,2-epoxypropyl)- g? phosphonate 14.1 176.25 352.5 55 Isdgggllrri-lncarboxymethylcellulose g g '67 As a result of the inverse solubility behavior of calcium Polysorbate 80 2 5 5 )(cis-l,2-epoxypropyl)-phosphonate, when aqueous suspen- Calcium e Benzyl alcohol 9 9 9 s1ons conta1n1ng up to 352.5 mg. drug per ml. are heated from watepfopinjecfion q-s. ad 10 ml L0 mL 10 ml 25 to 40C., the suspended particles increase in size from 10 to 20011.. The overall effect of this behavior is that aqueous 0 suspensions of the antibiotic agent tend to deteriorate both in terms f h i l Stability and appearance In the above formulations, the calcium (-)(c1s-1 ,2-epox- One object of the present invention is the preparation of yp pyn'p 15 a sollfllon 0f Sodlllm aqueous suspensions of Calcium (-)(Ci l,2-ep0xypropyl)- oxymethylcellulose and the m1xtu re ag tated to completely h h t bili d against i l i d i ti 55 wet the calcium salt. A colloidal drspersion of the lecithm 1s Th present i e io i b ed u on th di v th t added followed by the Polysorbate 80, calcium chloride, and aqueous pharmaceutical suspensions of calcium (-)(cis-l,2- the benzyl alcohol. The formula is brought to volume with e oxy ro yl)- ho honat an be stabilized against alteration water for injection. The suspensions are subject to autoclaving as a result of particle size growth due to variation in temperaat 121C. to effect sterilization. After sterilizing the suspenture by addition of certain additives to the suspension. It has sion, no change is observable in size or shape of suspended been discovered that the presence of low concentrations of a particles of calcium (-)(cis-l,2-epoxypropyl)-phosphonate combination of lecithin, Polysorbate 80, and sodium carboxfrom that of the calcium salt originally incorporated into the ymethylcellulose in aqueous solutions of the calcium salt, formulation at ambient temperature. When samples of the allow such suspensions to be heated and cooled without any 5 suspensions are heated to 121C. and cooled to 20C. then 7 appreciable change in particle size of the suspended material.

rewarmed to room temperature, no physical change in particle size of suspended material is observed upon microscopic examination.

EXAMPLE 2 EXAMPLE 3 Aqueous suspensions of calcium (-)(cis-l,2-epoxypropyl)- phosphonate suitable for ophthalmic use are prepared in the following manner:

Ingredients Concentration mgJml.

Calcium (-)(cis-1,2-epoxypropyl)- phosphonate Sodium carboxymethylcellulose Lecithin Polysorbate 80 Calcium chloride Phenethyl alcohol Water-for-injection q.s. ad

EXAMPLE 4 An aqueous suspension of calcium (-)(cis-1,2-epoxypropyl)-phosphonate is prepared using the same ingredients, proportions and procedure as Example 3 except benzyl alcohol is used in place of phenethyl alcohol. When the ophthalmic suspension is subjected to heating to 121C. and cooled to 20C. then rewarmed to room temperature, no physical change in particle size of suspended material is observed.

EXAMPLE 5 Aqueous suspensions of calcium (-)(cis-l,2-epoxypropyl)- phosphonate suitable for oral administration are prepared in the following manner:

Ingredients Concentration mg./5 ml.

Calcium (-)(cisl ,2-epoxypropyl-phosphonate 141 352.5 705 Sodium carboxymethylcellulose 20 Lecithin 1 5 20 20 LII Polysorbate 15 25 50 Sorbitol Solution 70% 1500 1500 1500 Sorbic Acid 5 5 5 Methylparabcn 6 6 6 Propylparaben 1 1 l Purified Water q.s. ad 5 ml. 5 ml. 5 m1.

In the above formulations, the calcium (-)(cis-l,2-epoxypropyl)-phosphonate is added to a solution of sodium carboxymethylcellulose and sorbitol solution 70 percent, and the mixture is agitated to completely wet the calcium salt. A dispersion is added containing the lecithin followed by the Polysorbate 80. A solution of the sorbic acid, methylparaben, and propylparaben is added. The formula is brought to volume with purified water.

EXAMPLE 6 Sterile aqueous suspensions of calcium (-)(cis-l,2-epoxypropyl)-phosphonate with disodium (-)(cis-l,2-epoxypropyl)-phosphonate in solution suitable for parenteral ad ministration are prepared in the following manner:

Ingredients Concentration mg./ml.

Calcium (-)(cis-1,2-epoxypropyl)-phosphonate 88.1 264.4 Disodium (cisl ,2-epoxypropyl)-phosphonate 83.7 83.7 Sodium carboxymethylcellulose 1.75 1.75 Lecithin 4 4 Polysorbate 80 10 12.5

Benzyl Alcohol 9 9 Water for Injection q.s. ad 1.0 ml. 1.0 ml.

In the above formulations, the calcium (-)(cis-1,2-epoxypropyl)-phosphonate is added to a solution of sodium carboxymethylcellulose, and the mixture is agitated to completely wet the calcium salt. A dispersion of the lecithin is added followed by the polysorbate 80 and the benzyl alcohol. The suspensions are sterilized by autoclaving at 121C. The disodium (-)(cis-l,2-epoxypropyl)-phosphonate is dissolved in water for injection and this solution is sterilized by filtration. The filtrate is aseptically combined with the suspension. The sterile suspension is brought to volume aseptically with sterile water for injection.

Polysorbate 80 is a complex mixture of polyoxyethylene ethers of mixed partial oleic esters of sorbitol anhydride; it is a viscous liquid with a density 1.06-1.10 and viscosity 270-430 centistokes.

What is claimed is:

1. The antibacterial pharmaceutical composition stabilized against particle size alteration comprising 2.8 to 35.2 calcium (cis-1,2-epoxypropyl)-phosphonate, 0.4 to 0.7 percent sodium carboxymethylcellulose, 0.5 to 0.6 percent lecithin, and 0.4 to 1.25 percent a complex mixture of polyoxyethylene ethers of mixed partial oleic esters of sorbitol anhydride having a density of 1.06-1.10 and a viscosity of 270-430 centistokes. 

